1. Field of the Invention
The present invention relates to an edible oils composition which can prevent an increase of the triglycerides in the blood of a person having eaten, as compared with conventional edible oils, is little accumulated in the body, is excellent in storage stability and flavor, and exhibits general-purpose properties (of being liquid even at low temperatures and being usable as a substitute for conventional cooking oils).
2. Description of Related Art
A human being takes the necessary calories mainly from sugars and lipids. However, the current tendency toward unbalanced intake of nourishment and/or intake of excess calories promotes obesity and is causative of degenerative diseases or other problems. In particular, the lipidic intake has recently increased in the dietary habits of advanced nations, which brings about an increase in blood triglyceride level and obesity and presents an important cause of degenerative diseases. Since the blood triglyceride level and blood cholesterol level have a close relation with arteriosclerosis, it is particularly essential to the prevention of degenerative diseases to keep these levels low, and education is therefore made in advanced nations for the purpose of keeping the levels low. In fact, however, the number of deaths from circulatory degenerative diseases is steadily increasing.
In general, a food prepared by using much lipids (such as fats and oils) is good and a man of the present age becomes used to such a food, which is a reason for the above problematic tendency. The tendency is found even among Japanese peoples who took a little lipid, and the rate of the lipidic intake to the total energetic intake has increased three-fold in the last 50 years. Under these circumstances, several low-calories substitutes for fats and oils were developed by making the properties of a protein or sugar approach those of fats and oils, and proposed for the purpose of reducing the lipidic intake. However, these substitutes could not satisfactorily be substituted for fats and oils in respects of flavor, palatability and physical properties. Further, the substitutes failed in fulfilling another role of fats and oils, i.e., the role as a heating medium in cooking. It is therefore considered that if fats and oils which exhibit flavor, palatability and physical properties equivalent to those of currently used fats and oils can be used as a heating medium and can inhibit the postprandial increase in blood triglyceride level is developed, it will become possible to inhibit obesity to thereby lower the morbidity rate of degenerative diseases.
Unabsorbable fats and oils have recently been developed extensively as described below. For example, there have been proposed sucrose-fatty acid polyesters (Mattson et al., U.S. Pat. No. 3,600,186). These polyesters are not absorbed into the body, but are excreted, so that these oils provide no calorie. However, liquid sucrose-fatty acid polyesters pose problems of causing anal leakage, hindering the absorption of fat-soluble vitamins, and so on, because they are unabsorbable fats and oils. The use was authorized by FDA on Jan. 30, 1996, under the restriction that semi-solid or solid sucrose polyesters having a melting point of 37.8 to 71.1.degree. C. and containing vitamins A, D, E and K in predetermined amounts respectively are applied only to salty snack foods. The restriction was made for the purposes of protecting the absorption of fat-soluble vitamins from the above hindrance and inhibiting anal leakage. This fact means that the substitutes for fats and oils are not satisfactory in general-purpose properties.
It has been known to the public that a medium-chain fatty acid triglyceride (MCT) does not accumulate in the body. However, MCT exhibits a problematic smoke point of as low as 160.degree. C. or below in cooking, so that the use of MCT as a cooking oils is unsuitable.
Further, there have been proposed triglycerides having both a long-chain saturated fatty acid (such as behenic acid) and a medium-chain fatty acid having ten or fewer carbon atoms (Seiden: JP-A 2-1799) and triglycerides having both a long-chain saturated fatty acid (such as stearic acid) and a short-chain fatty acid (Chrysam: JP-A 6-506106). It is expected that these triglycerides prevent an increase of the blood triglyceride level of a person having eaten, and therefore can be used favorably as fats and oils substitutes preventing degenerative diseases, because they contain long-chain saturated fatty acids which are little absorbed into the body and medium- or short-chain fatty acids which are not accumulated in the body. However, the glycerides are solid and therefore are poor in the general-purpose properties.
An edible oils and fats composition is disclosed in U.S. Pat. No. 4,976,984, which comprises phospholipids and glyceride mixtures containing diglycerides in an amount of 5 to 100%. Further, a serum triglyceride level lowering agent and a weight-increase inhibitor containing a diglyceride as the active ingredient are disclosed in JP-A 4-300 825 and JP-A 4-300 826.
Further, a fats and oils composition is disclosed in JP-A 8-60180, which comprises afats and oils component, containing a diglyceride consisting of a long-chain fatty acid and a short-chain fatty acid, as a constituent fatty acid.